Ah, the good ol' dilemma of whether or not to risk a friendship for a relationship. I have told more than one friend that I like them, and it did not destroy our friendship, even after I was rejected. Therefore, I think that you have more to gain than to lose. If in the off chance that he does not like you "like that," it may be awkward for a couple of hours or days, but if you guys are really good friends, that will continue.
Telling someone how you feel about them is also a great relief of your chest. It will pretty much eat away at you until nothing is left if you keep it in. I have always felt better after admitting my feelings to someone.
So, go for it!